from PyQt5.QtCore import pyqtSignal
from PyQt5.QtWidgets import QComboBox


class MyComboBox(QComboBox):
    clicked = pyqtSignal()  # 创建一个信号

    def showPopup(self):  # 重写showPopup函数
        self.clicked.emit()  # 发送信号
        super(MyComboBox, self).showPopup()  # 调用父类的showPopup()
